A hook assembly, also referred to as a hook, is used to carry a load. Some types of hooks are designed to receive ropes, slings, straps or other flexible members that are in turn fastened to a load to be carried, such as by a crane or other lifting device.
Hooks are subject to movement during lifting and lowering operations, and they may make contact other objects causing a change in position that can lead to an inadvertent release of the rope or any other object carried by the hook.
Some hooks are carefully designed to have a geometry tending to prevent such inadvertent release. In some scenarios, it would be desirable to provide additional assurance against a rope or other object from becoming inadvertently released from a hook.